Instant water heater

ABSTRACT

An improved portable water heater for use in outdoor camping, with trailers, and pickup campers, etc. that will rapidly heat quantities of water efficiently and safely. Heat is generated by burning bottled propane gas delivered through a simple and efficient burner apparatus, which directs the heat from the burning gas into a water heating system through which water is circulated to be quickly heated. The improved water heater includes means for alternatively pumping water from a built-in water supply, or through a hose connected to or immersed in an external water source. The temperature of the hot water generated is regulated by the volume of water that a pump located between the water source and the water heating system forces through the water heating system.

1451 Oct. 30, 1973 United States Patent 1191 Williams INSTANT WATER HEATER Primary Examiner-William F. ODea Assistant Examiner-William C. Anderson 1d 11. W11 43 W. 100 Invent Gm AttorneyB. Deon Criddle South, Smithfield, Utah 84335 Nov. 3, 1971 Appl. No.: 195,281

[22] Filed:

ABSTRACT 52 US. 126/350 R, 122/115 camping, with trailers, and Pickup campers, that 51 11101 2411 l/06 will rapidly heat quantities of water efficiently and Field of Search............................ Safely- Heat is generated by burning bottled Propane gas delivered through a simple and efficient burner apparatus, which directs the heat from the burning gas [56] References Cited into a water heating system through which water is cir- UNITED STATES PATENTS culated to be quickly heated. The improved water heater includes means for alternatively pumping water from a built-in water supply, or through a hose con- 431/173 nected to or immersed in an external water source.

431/185 The temperature of the hot water generated is regu- FOREIGN PATENTS OR APPLICATIONS 3,131,713 5/1964 1,777,411 10/1930 Mayr...............

1,619,171 3/1927 Wallis et a1. 1,656,907 1/1928 lated by the volume of water that a pump located between the water source and the water heating system forces through the water heating system.

671,009 4/1952 Great Britain 126/350 R 1,022,060 3/1966 Great Britain 126/350 R 5 Claims, 7 Drawing Figures PATENIEDUBI 30 Ian 3; 768.458

sum 1 or 2.

ATTORNEY PATENIEDUCT 30 ms 3. 768,458

sum 2 0F 2 .FIG 7 INVENTOR. GAROLD H. WILLIAMS KAQ 42264 ATTORNEY INSTANT WATER HEATER BRIEF DESCRIPTION OF THE INVENTION 1. Field of the Invention This invention relates to hot water heaters and is particularly concerned with a compact, portable, low-cost, instant water heater such as might be suitable for use by tent campers or owners of mobile camp trailers and truck-camper combinations.

2. Prior Art As is more particularly pointed out in my co-pending U.S. patent application Ser. No. 14,045 filed Feb. 25, 1970, now U.S. Pat. No. 3,687,128, granted Aug. 29, 1972, there has long been a need for a water heater that can be used by outdoor enthusiasts to conveniently and efficiently produce quantities of hot water. In the past, it has been necessary for an outdoors camping enthusiast to heat water as needed over an open fire or over a camp stove'utilizing a gas, charcoal or some other such available fuel. While water heating devices utilizing coils having water passing therethrough and surrounding an open flame, have been proposed and used in the past. for various purposes, none to my knowledge, have been available in a portable, compact water heater. More particularly, the prior art water heating devices have not to my knowledge provided a burner and related water heating system which will efficiently and safely heat water in such a portable system. Nor have former systems incorporated a reservoir or water source and a regulating pump combined such that the resulting unit can be readily transported from place to place.

The water heating unit disclosed in my aforementioned application for patent provides a heater which will instantly produce hot water and which is truly portable while still being safe to operate. The positioning of the pumping means upstream from the heating system eliminates entrapment of water within the heating system and the resultant possibility that a dangerous head of steam pressure could be built up therein. The aforementioned application also discloses heating units wherein a reservoir is included within the heater housing itself or wherein the heating unit can be connected to any outside reservoir.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved instant hot water heater that will efficiently heat water to even very high temperatures and to provide means whereby the water temperature can be regulated by varying the volume of flow through the heater system.

' Other objects of the invention are to provide a portable instant water heater which can selectively draw water from a self contained reservoir or through a line from a water supply which is external to the water heater.

Another object is to provide a portable instant water heater which has a simple, inexpensive burner assembly that efficiently burns a combustible gas introduced therein.

Still another object is to provide a simplified, relatively inexpensive water heating system through which water is readily circulated, with the flame from the burner assembly directed thereupon.

Principal features of the present invention include an instant hot water heater of the general type disclosed in my aforementioned co-pending U.S. patent application but including valve and vent means to allow selective use of a built-in reservoir or an outside separate supply-of water.

A simplified burner having an effective mixing structure, whereby air is entrained within pressurized gas, is provided. The burnable gas is delivered into the cylindrical burner tangentially and at a slight upward angle, with respect to the normal horizontal operating position of the water heating system.

The gas and air mixture introduced thus swirls within the burner and moves upwardly and out of the burner into the water heating system even as it is burned. The vortex created by the swirling fuel mixture pulls additional air into the burner through a central hole in the bottom of the burner thereby giving an optimum gas air mixture. This mixture, when burned, produces an intense heat that is directed by the cylindrical burner against and into the water heating system.

The water heating system consists of at least one cylindrical element which is closed at both ends and has intake and output water lines fixed therein. The cylindrical element has a number of heat transmitting tubes fixed longitudinally through it. Water is circulated around the tubes and heat from the burner is directed through the tubes to exhaust. The water heating element is positioned adjacent to the internal reservoir so that a pre-warming of water within that reservoir occurs when the burner is operated. Ths possibility of a pressure build up within the reservoir is eliminated by forming a vent through the reservoir lid.

Safety means are also provided between the water heater element and an output spout such that in the event the spout should become clogged, the water will be circulated back through the water heater reservoir.

Additional objects and features of the invention will become apparent from the following detailed description and drawings, disclosing what is presently contemplated as being the best mode of the invention.

THE DRAWINGS In the drawings:

FIG. 1 is a side elevation view of the invention;

FIG. 2, a similar view of the other side, but showing the raised carrying handle in phantom lines;

FIG. 3, a top plan view;

FIG. 4, a vertical section, taken on the line 4-4 of FIG. 3;

FIG. 5, an exploded view of the valve assembly shown within line 5-5 of FIG. 4;

FIG. 6, an enlarged transverse vertical section through the burner assembly; and

FIG. 7, a horizontal sectional view taken on the line 77 of FIG. 4.

DETAILED DESCRIPTION Referring now to the drawings:

In the illustrated preferred embodiment, the water heater 10 includes a housing 11 on the side of which is releasably mounted a presurized propane gas cylinder 12. A water pump 16 is held by screws 16a, on the top of the housing along with bail-type carrying handle 17. A burner assembly 13, a water heating aysembly l4, and a water reservoir 15 are positioned within the housing 11. A filler spout 15a through the top of housing 11 provides a means for filling reservoir 15. A discharge spout 18 extends through the side of housing 11 and is connected by a conduit 19 to the output end of the water heating assembly 14.

As will be further explained, heat generated by the burner assembly passes through the water heating assembly 14 and out through a screen covered vent 20 in the housing. Conduit 19 has a portion 19a extending within the path of heat generated by the burner assembly and a portion 19b that extends through reservoir 15. A safety pressure relief valve 21 is connected in portion 19b of conduit 19 within reservoir 15. The valve 21 opens to exhaust into reservoir 15, when the pressure in line 19 or in the water heating system 14 reaches a pre-set valve.

A valve 22, shown exploded in FIG. 5, provides means whereby an operator can selectively draw water from reservoir 15, or can draw water into the water pump 16 from an outside source. The valve 22 includes a tubular insert 23 which fits within a sleeve 24 that is the end of a water supply line 25. A rod 26 extends as a handle normal to one end of insert 23, and holes 27 and 27a are formed in the wall of the insert 23 at its other end. Holes 28 and 28a are formed through the wall of a sleeve 24 so that they will align with holes 27 and 270 when insert 23 is fitted therein and handle 26 is turned to the position shown by solid lines in FIG. 5. When the holes 27, 27a and 28, 28a are aligned, an unobstructed passage is provided from the reservoir 15 through holes 27, 27a and'28, 28a of the valve 22 which is positioned to place the holes in the bottom of the reservoir 15, and the line which connects the valve and the intake of the pump 16. A cap 30 fits over the end of insert 23 extending from the housing 11 to keep water from reservoir 15 from flowing out of insert 23 rather than being pumped through line 25. When insert 23 is rotated to the phantom line position of handle 26 shown in FIG. 5, the holes 27, 27a and 28, 280 are out of alignment and water cannot enter the valve 22. Cap 30 is removed and an inlet tube, not shown, has one end telescoped on the insert in place of the cap. The other end of the tube can be immersed in an available external source of water or other liquid. Operation of pump 16 then draws the liquid through insert 23 of valve 22 and through line 25. Water or other liquid can, therefore, be alternatively drawn from the self contained reservoir 15 or from an external source as desired by an operator.

In operation, pump 16 is operated by oscillating pump handle 16b back and forth. This action draws water from either reservoir 15 or from an exterior source through intake line 25, as has been explained, and forces it through a pump discharge line 31. Line 31 extends from the pump 16 to the bottom of the water heating system 14. The volume of water pumped is dependent upon the speed of oscillation of the pump handle 16b.

The water heating system 14, shown best in FIGS. 4 and 7, consists of an upstanding cylinder 32 which is closed at both its top and bottom ends. The pump discharge line 31 serves as a water input line to the bottom of the closed cylinder and the outlet conduit 19 carries water from the top of the cylinder to a spout 18. A plurality of hollow, heat conductive tubes 33, constructed of copper or other good heat conductive material,

which are open at both ends, are passed through the 6 cylinder 32 and allow flow of heat from the burner assembly 13 to and out through an exhaust port 20 at the top of the side wall of housing 11.

Burner assembly is fed a combustible gas from a pressurized gas cylinder 12, through a line 34. The volume of gas introduced into the burner assembly is controlled by a manual shut-off valve 35 in the line 34. Cylinder 12 is releasably secured to the side of housing 11 by a conventional clamping strap 36 and line 34 is secured to the inlet end of the intake pipe 37 of the burner assembly 13 in conventional fashion by a clamping nut 38. Pipe 37 is secured to a support bracket 39 which extends diametrically across housing 11 at the bottom thereof, by a bolt 40 which projects downwardly from the bottom of the pipe and a nut 41. Line 34 is maintained at a slightly upward angle with respect to intake pipe 37 so that gas moving into a burner bowl on the end of pipe 37, through the pipe is injected at an upward angle. Pipe 37, as shown in dotted lines in FIG. 7, extends into burner bowl 43 and enters the bowl tangentially. Thus the entering gas moves spirally upwardly as a vortex which tends to form a vacuum in the bottom of the burner bowl 43. Air is drawn into the low pressure area through a center opening 44 in the bottom of the burner bowl 43, and through angled holes 45 formed around the opening 44. The holes 45 are angled in the direction of flow of the gas in the burner bowl 43 so that air sucked into the bowl 43 is entrained in the swirling gas. Additional air is also entrained in the gas mixture through ports 46 in the intake pipe 37. The arrangement of line 34, pipe 37 and ports 46 creates a Venturi action to pull in the additional air. An optimum gas-air mixture is thereby created that when ignited will efficiently heat the water heating system 14. The burner assembly can be ignited by a match or by a conventional manually operated spark igniter, not shown.

Air holes 11b are provided around the base of housing 1 1 to prevent a heat build up of heat therein and the lower edge of housing 1 l is fitted into a cushioning strip 47 that provides protection to the housing edges when the water heater 10 is placed on the ground and to other surfaces when the heater is used thereon.

Since lines 25 and 31 are within the reservoir a noncorrosive and flexible material such as plastic can be used in their construction, and the surrounding water therein protects them from being burned or flame damaged. However, since the wall of the reservoir, along with tubes 33 serves as a heat duct the water in the reservoir is heated somewhat even as the heating unit 14 is heated. Thus a pre-heating of the water in the reservoir is obtained before it is moved into the heating unit 1 14. A lid 48 that covers the filler spout 15a to reservoir 15 has a hole 48a therein it to allow any steam or pressure built up in the reservoir to escape.

Although a preferred form of my invention has been herein described, it is to be understood that the present disclosure is made by way of example and that variations are possible without departing from the scope of the hereinafter claimed subject matter, which subject matter I regard as my invention.

I claim:

1. An improved portable, instant hot water heater comprising a housing;

a burner unit mounted in a lower end of the housing and having a fuel nozzle directed upwardly into the housing;

vent means through a wall of the housing at the upper end thereof through which heat from the burner assembly is exhausted;

liquid heating means providing means for circulating liquid therethrough, said liquid heating means being positioned within the housing and between the burner assembly and vent means and having means for conducting heat from the burner unit therethrough in close proximity to the means for circulating liquid therethrough;

a water reservoir within the housing;

valve means for selectively connecting the means for circulating liquid in the liquid heating means with the said reservoir or with connection means to an outside water source;

pump means having an intake and an outlet on the housing;

means coupling the intake of the pump means to the valve means, and the outlet of the pump means to the liquid heating system, whereby liquid is pumped from the valve means into the means for circulating liquid;

a spout extending from the housing;

a conduit connecting the means for circulating liquid and the spout;

a source of combustible gas under pressure;

gas conduit means interconnecting the said source and the said fuel nozzle; and

valve means controlling flow between the source and the fuel nozzle.

2. An improved portable, instant hot water heater as in claim 1, wherein the burner unit is composed of a circular burner bowl having a straight upstanding wall and open at its top; and an intake pipe extending tangentially and angularly upwardly into the burner bowl, whereby gas introduced through the pipe to the interior of the burner bowl swirls upwardly to the top of the bowl.

3. An improved portable instant hot water heater as in claim 2, wherein the burner bowl has a hole formed axially through its bottom at the center thereof and at least one angled air hole journaled through the said bottom of the burner unit between the said center hole and the upstanding bowl wall, each said air hole being angled in the direction of travel of the swirling gas, whereby air is entrained in said gas.

4. An improved portable instant hot water heater as in claim 2, wherein the intake pipe has at least one air intake hole formed therein and surrounds the end of the gas conduit means whereby a Venturi is formed and air is entrained in gas entering the intake pipe from the gas conduit.

5. An improved portable instant hot water heater as in claim 1, wherein handle means for turning said insert. 

1. An improved portable, instant hot water heater comprising a housing; a burner unit mounted in a lower end of the housing and having a fuel nozzle directed upwardly into the housing; vent means through a wall of the housing at the upper end thereof through which heat from the burner assembly is exhausted; liquid heating means providing means for circulating liquid therethrough, said liquid heating means being positioned within the housing and between the burner assembly and vent means and having means for conducting heat from the burner unit therethrough in close proximity to the means for circulating liquid therethrough; a water reservoir within the housing; valve means for selectively connecting the means for circulating liquid in the liquid heating means with the said reservoir or with connection means to an outside water source; pump means having an intake and an outlet on the housing; means coupling the intake of the pump means to the valve means, and the outlet of the pump means to the liquid heating system, whereby liquid is pumped from the valve means into the means for circulating liquid; a spout extending from the housing; a conduit connecting the means for circulating liquid and the spout; a source of combustible gas under pressure; gas conduit means interconnecting the said source and the said fuel nozzle; and valve means controlling flow between the source and the fuel nozzle.
 2. An improved portable, instant hot water heater as in claim 1, wherein the burner unit is composed of a circular burner bowl having a straight upstanding wall and open at iTs top; and an intake pipe extending tangentially and angularly upwardly into the burner bowl, whereby gas introduced through the pipe to the interior of the burner bowl swirls upwardly to the top of the bowl.
 3. An improved portable instant hot water heater as in claim 2, wherein the burner bowl has a hole formed axially through its bottom at the center thereof and at least one angled air hole journaled through the said bottom of the burner unit between the said center hole and the upstanding bowl wall, each said air hole being angled in the direction of travel of the swirling gas, whereby air is entrained in said gas.
 4. An improved portable instant hot water heater as in claim 2, wherein the intake pipe has at least one air intake hole formed therein and surrounds the end of the gas conduit means whereby a Venturi is formed and air is entrained in gas entering the intake pipe from the gas conduit.
 5. An improved portable instant hot water heater as in claim 1, wherein the valve means comprises a sleeve in the reservoir having one end connected to the means coupled to the intake end of the pump and having at least one hole in the wall of the sleeve within the reservoir; a tubular insert open at both ends and having one end journaled in the sleeve, and said tubular insert having a hole through the wall thereof adapted to be turned into and out of alignment with the hole in the wall of the sleeve and the other end projecting from the housing; and handle means for turning said insert. 